Open Source Desktop GIS

There is an extremely active open source community specializing in numerous geospatial applications. Many of these tools have been built from scratch, while others provide geospatial add-ons and interfaces to existing open source products such as relational databases.

One indication of the variety of open source geospatial software projects currently underway is the list given in the website of the Open Source Geospatial Foundation (OSGeo). OSGeo provides support and incubation services to new geospatial projects. Major categories of supported projects include web mapping, desktop GIS, and geospatial libraries.

The category of “geospatial libraries” includes development tools used by programmers in coding their applications, libraries of utility routines (such as raster and vector data conversion routines and map datum/projection transformation routines), and other tools. These tools can be used directly by users (usually as command-line programs), or have been incorporated into various open source desktop GIS and web mapping software applications.

The web mapping tools are discussed in a subsequent subsection. These include tools for creating interactive web maps for public display and interaction, as well as tools for hosting the data layers used in such web applications. Data layers are often created using desktop GIS products and stored in geodatabases or in stand-alone GIS data files.

The most important tools for the participants in the project are the desktop GIS products, used in making GIS data products for their LUG's planning and administrative activities. (The figure above shows the main screen of MapWindow GIS.)

Some Available Open Source Desktop GIS Tools

The OSGeo web page cited above lists only three of many available desktop GIS products. There are many other similar products not listed there, varying in complexity and in their intended purpose. Some are more suitable for general GIS work, including map preparation and some spatial analyses. Others specialize in geostatistical and raster analysis rather than map production.

Use of open source GIS tools in desktop environments is described in the currently out-of-print book Desktop GIS by Gary Sherman. * The book includes a figure, reproduced below, showing some open source GIS applications and their suitability to users of various “personas:”

User Persona

GIS Software Usage Pattern

Casual

Data visualization only

Intermediate

Data creation and map composition

Advanced

Geospatial analysis

From these definitions, our project participants have (or will have, by the time they get started) “Intermediate” personas.

More recently, Steiniger and Hay (2009) published a study of FOSS in the geographical information sciences, examining their utility in the field of landscape ecology and comparing their features with ESRI's proprietary ArcView 9.3 (without any extensions). Table 2 of their paper, reproduced below, lists the eight open source GIS packages examined in detail.

Similar to the Sherman figure reproduced above, it shows the target user “personas” of the individual packages. These personas are:

User Persona

GIS Software Usage Pattern

Novice

Viewing

Experienced

Editing and simple analysis

Expert

Geospatial analysis

Research

Scripting, programming

By the persona categories of Steiniger and Hay, our project participants fall in the “Experienced” category.

The authors note that individual open source GIS packages often have a unique data focus. Some packages like GRASS and SAGA are intended for raster and geostatistical analyses, while others like Quantum GIS, MapWindow, and uDig have more of a vector analysis emphasis, as shown in the table.

The authors note that while the capabilities of the open source packages as a whole are roughly equivalent to the capabilities of ESRI's ArcView 9.3 product, the open source packages in general lack ArcView's sophisticated map composition and quality output capabilities. They further note that this is typically not a problem for scientific publication. Open source GIS packages' plotting and screen shot functions, in combination with available graphic layout and composition software (such as GIMP and Inkscape), allow for creation of professional-quality maps and illustrations.

Steiniger and Hay (2009, page 190) also comment:

Interestingly, this focus on certain GIS tasks by the free software projects has resulted in an open-minded and flexible FOS GIS user community that chooses the best software for each task to accomplish. This might be found cumbersome by some, but it ensures that research is not limited by the functionality provided by one particular software and also results in a well skilled user community that understands the underlying principles and not only “presses buttons.”

This project's choice of tools partially illustrates the above observation, as will become apparent in the following subsections.

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* - An updated edition of this book is available as The Geospatial Desktop (2012) from Locate Press. See References section for information.

This document was originally published in partial fulfillment of the requirements of the MGIS degree by Howard Yamaguchi, enrolled at that time in the MGIS program of The Pennsylvania State University (graduated December 2011). Additional information is being placed in this website from time to time, as are edits to existing content. Website content management by Google™ Sites.